I have a 315G tank that I am considering planting. I just got my hands on a slew of T-8 fixtures that will give me the light I need. I keep reading about the watts per gallon ratio and thats what I dont understand. Watts is the energy used by the bulbs, lumens is the output of the bulbs, and kelvin is the color of the bulbs. It seems to me that lumens per gallon is what we should be looking at. Am I looking at this the wrong way?
What part of plant lighting am I mis-understanding?
- Thread starter BadOleRoss
- Start date
But.....that's wrong! 
Just cause it's easy doesn't make it right!
OK, that lumens per gallon is a good target range?
Just cause it's easy doesn't make it right! OK, that lumens per gallon is a good target range?
not sure, but the watts per gallon rule is only part of the picture. there are many other factors that help determine the ability to grow plants, like your fertilizer schedule, tank depth (shallower is easier to grow plants). light coverage (no dark spots)
and I say this from experience. in the past, I have easily grown giant sword plants, val, lotus, crypts etc. simply with good fertilizers every week, good light coverage, and only about 1 watt per gallon.
eg. two 20w tubes on a 30g or 2 40w tubes on a 4 foot 65g etc. using Hagen powerglo normal T8's.
if you go to the plant forums they would say it would never work.
but it does.
also, with the new T5, T5 HO and Power compact lighting, the WPG rule goes out the window. these newer lights are more efficient and put out much more lumens per watt than regular old flourescents.
and I say this from experience. in the past, I have easily grown giant sword plants, val, lotus, crypts etc. simply with good fertilizers every week, good light coverage, and only about 1 watt per gallon.
eg. two 20w tubes on a 30g or 2 40w tubes on a 4 foot 65g etc. using Hagen powerglo normal T8's.
if you go to the plant forums they would say it would never work.
but it does.
also, with the new T5, T5 HO and Power compact lighting, the WPG rule goes out the window. these newer lights are more efficient and put out much more lumens per watt than regular old flourescents.
I am getting the impression that this is one of those things where there are a lot of "general rules" but you just need to find out what works for you! I know t-5s are the way to go, I had them on my SW set up. But, I picked up 6 8' long T-8 fixtures for $10. Even using a standard t-8 6500 sunlight bulb I can get 1.7wpg. Not a bad place to start. Changing some of the bulbs out to better 40w bulbs will raise that number. I have a DIY reflector that will cover all of the lights but I am still dealing with a tank that is 28" deep!
yep i completely agree12 Volt Man;3997591; said:
the new T5's produce about 20% more light for about 90% of the wattage(of t8's) and power compacts are t5's that have basicaly been bent in half so get TWICE as much light as that in the same space the HO T5's are actualy less efficient (go ahead plant keepers as shocked as you are go look it up) than normal T5's *GASP* but have a much higher wattage on them (so overall less lumens per watt but about twice as many watts)
i didn't mean it like that HO is very worth it becuase of the higher wattage in a smaller space but it's just technicaly it has only slightly better efficiency than T8's and atleast 10 lumens less per watt than standard T5'sBadOleRoss;3997799; said:
Well, for what I paid for my T-8s, I'll give them a try. This is my first attempt and a planted tank so I dont want to sell the farm just yet.
True.So true.BadOleRoss;3997694; said:
The easiest,and maybe even the nicest,planted tank I have has a single T8 GE bulb that I get at Wal Mart.BadOleRoss;3998018; said:
I agree with the plants here. I would add wisteria,and java ferns to that. With these plants,I would not even mess with ferts at first.They may cause algae to grow. Vals can be touchy IME. But I have gotten them to grow in lowlight.12 Volt Man;3997591; said:
Trial and error is the best advice.Once you find plants you can keep healthy,the rest will be easy.
Good Luck!